The long-term goal of this research is to increase knowledge about reinforcement mechanisms underlying adolescent smoking by examining the impact of alternative reinforcers on smoking behavior. This programmatic series of studies is designed to yield findings that will enhance the viability of contingency management (CM) interventions, and behavioral interventions more broadly, for adolescent smokers. The specific aims of the project are: 1) to investigate whether smoking choices will decrease systematically with an increasing magnitude of an alternative monetary reinforcer, and whether rate of decrease will be moderated by baseline smoking level; 2) to investigate whether the probability of monetary reinforcement (certain vs. probabilistic) affects smoking choice behavior, and whether this behavior is moderated by baseline risk-taking level; and 3) to investigate whether nonsmokers, lighter smokers and heavier smokers vary in the availability and use of non-smoking reinforcers in the natural environment. Three studies are planned. Studies 1 and 2 manipulate alternative reinforcers within-subjects to test effects on the relative reinforcement value of smoking. Study I is a laboratory choice experiment (N=84) that examines the effects of the magnitude of an alternative monetary reinforcer on the relative reinforcing value of smoking in a 4- session counterbalanced protocol. Study 2 (N=84) uses a 3-session counterbalanced laboratory choice protocol to examine adolescent preferences for smaller but certain monetary reward versus larger but probabilistic monetary reward by comparing choices for each in contrast to opportunities to smoke. Study 3 is an assessment study comparing community samples of smokers (N=124) to a matched sample of nonsmokers (N=96) with respect to the availability and use of alternative reinforcers in their natural environment. Identifying salient reinforcers for adolescents that are unrelated to or inconsistent with smoking may be essential for enhancing the future impact of CM and other behavioral interventions for adolescent smoking cessation. Complementing this research, a Community Advisory Board will provide guidance on practical means of implementing alternative reinforcement strategies to reduce adolescent smoking. Study findings will advance our understanding of reinforcement mechanisms underlying adolescent smoking, which could also have implications for understanding and treating adolescent drug use more generally.